In recent years, an increasing number of portable display devices requiring operations such as menu selection are provided with a touch panel with which an operation such as selection of a desired menu is accepted by pressing the panel using a stylus pen or a finger according to the display in the screen. Such portable display devices employ various well-known methods, such as a resistive type, an electrostatic capacitance type, an optical sensor type, and an infrared type, in order to specify a position that has been pressed of the panel.
Further, in recent years, a display screen of such portable display devices is configured by two screens (typically, center spread), as it is preferable that the display screen account for a larger portion of a housing surface. Moreover, some displays are configured such that two screens are connected without a seam (seamlessly).
Japanese Patent Application Laid-open No. 2006-53678 discloses a structure of a notebook computer having such a two-screen touch panel, and a configuration of a user interface, such as a virtual keyboard and a virtual mouse, on a display screen of the device.